Clutch.



'PATENTED MAY 12, 1903.

0. B. POLLARD.

CLUTCH. APPLICATION FILED 061213, 1902.

.H0 MODEL.

FIG, 2,

INVENTOR:

WITNESSES:

mu, WASNKNGTON n c NiTE STATES PATENT Patented May 12, 1903.

OFFICE.

CHARLES E. POLLARD, OF BROOKLYN, NEW YORK, ASSIGNOR TO E. W. BLISS COMPANY, OF NEW YORK, N. Y., A CORPORATION OF WEST VIRGINIA.

CLUTCH.

SPECIFICATION forming part of Letters Patent No. 727,683, dated May 12, 1903.

Original application filed March 7, 1902, Serial No. 97,123. Divided and this application filed October 13,1902. Serial No. 126,995. (No model.)

To all whom it may concern.-

Be it known that I, CHARLES E. POLLARD, a citizen of the United States, residing in the borough of Brooklyn, county of Kings, city and State of New York, have invented certain new and useful Improvements in Clutches, of which the following is a specification.

My invention aims to provide certain improvements in clutches whereby they may be freed to a considerable extentfrom shocks which ordinarily occur and which cause a considerable loss by breakage of clutch-pins.

My invention also provides certain improvements hereinafter referred to in detail.

The accompanying drawings illustrate a clutch in which my invention is embodied.

Figure 1 is a view, partly in side'elevation and partly in section, showing a complete clutch containing my improvement. Fig. 2 is a section of Fig. 1 approximately on the line 2 2 with the outer cap removed. Fig. 3 is a section on the line 33 of Fig. 1. Fig. 4 is a fragmentary elevation of a part of Fig. 1.

My improvement is applicable to a great variety of clutches. It is shown as applied to a clutch in which a shaft and a surrounding hub are arranged to be clutched together by means of an oscillating key seated in one of said parts. Such clutches are commonly used in power presses.

In presses at present in use it is common to employa compound die including a heavy spring which during the pressing movement of the crank or similar member of the machine is put under compression, so that the instant the crank passes the dead-center the spring thrusts it up with an enormous force and turns the driven shaft ahead of the driving-hub, causing the key to move in the recess suddenly from the rear wall thereof against the front wall with a considerable shock. In other types of clutch and in other machines analogous conditions occur, forcing the driven member suddenly ahead of its driver. In order to prevent these excessive sh0cks,myinvention provides a holding-back pawl, which when the parts are clutched to gether serves to hold back the driven part and prevent its moving forward relatively to the driving part. The pawl of my invention is simple and stronglymade by mounting it on the shaft and preferably passing it through the shaft and outward thereof at bothends and, by pressing it in. an axial direction against the face of the hub, the said face being provided with one or more coacting ratchet-teeth in position to be engaged by the pawlsimultaneously with the clutching movement ofthe clutch.

Referring to the drawings, A indicates a shaft, and B a hub, which is provided with v a bushing B,'keyed thereto, so as to form substantially a part thereof. A recess C is provided in the shaft, in which is seated an oscillating clutch-key D, made in' accordance with my application for patent filed March 7,

1902, Serial No. 97,123, of which this application is divisional. The inner collar E and the outer collar or cap F provide bearings for the cylindrical ends of the key D. The key is provided with an arm G for oscillating it. As the bushing B is rotated in the direction of the arrow, Figs. 2 and 8, the stop H, which is normallyin the path of the arm G, thrusts the arm to the position of Fig. 3, so that the recess J in the bushing is freed from the key. When, however, the stop H is turned out of the path of the arm by pressing a pedal connected with the rod -K, Fig. 1, a spring L turns the key D into the recess J as the latter arrives at apoint opposite the key, and the hub in its continued rotation carries the shaft with it. 7 The key is shown as engaging the recess J in Fig. 2..

M is a stop limiting the forward movement of the arm G under the pressure of the spring L. The parts L and'M are mounted on the inner face of the collar E.

For holding back the shaft, so that when the crank passes the dead-center, or at any other time, the shaft shall not be turnedforward relatively to the huh, I provide a-pawl which preferably consists ofa rectangular bar N, extending through the outer end of the shaft adjacent to the outer face'of the hub and projecting beyond the same at opposite ends. The pair of springs O 0' press the same forward, and a pin P projects out- Ward beyond the end of the shaft for manipulating the pawl from outside. In the face of the hubI provide a pair of coacting ratchetteeth having their abrupt shoulders formed, preferably, of pins Q of hardened steel. As the hub B is rotated the recess J comes opposite the key D in the shaft, and simultaneously the pawl N clicks over the abrupt face of the ratchet-tooth. If then the key D is turned to clutch the parts together, (see Fig. 2,) the shaft A is not only turned forwardly by the hub through the key D, but is held back from turning forward relatively to the hub by means of the pawl N pressing against the pin Q.

Though I have described with great particularity of detail a clutch embodying my invention, yet it will be understood that the invention is not limited to the particular embodiment disclosed. Various modifications in the details and combination of parts are possible to those skilled in the art without departure from the invention.

What I claim is l. The combination with a shaft, of a hub surrounding the same, a clutch adapted to connect said shaft and hub whereby one is driven by the other, a pawl on said shaft outside of said hub and pressed in an axial direction against the face of said hub, and a coactin g ratchet-tooth on said face, said pawl being arranged to act simultaneously with said clutch to hold back the driven part and prevent its moving forward relatively to the driving part.

2. The combination with a shaft, of a hub surrounding the same, a clutch adapted to connect said shaft and hub whereby one is driven by the other, a pawl passing through said shaft and extending outward thereof at both ends, means for pressing the same against a face of said hub, and coacting ratchet-teeth on said face, said pawl being arranged to act simultaneously with said clutch to hold back the driven part and prevent its moving forward relatively to the driving part.

3. The combination with a shaft, of a hub surrounding the same, a clutch adapted to connect said shaft and hub whereby one is driven by the other, a pawl consisting of a harNextending through the outer end of the shaft adjacent to the outer face of the hub, and projecting beyond the shaft at opposite ends, a spring for pressing said pawl against the face of said hub, a pin connected to said pawl and extending outward beyond the end of the shaft for manipulating the pawl, and coacting ratchet-teeth on the face of the hub, said pawl being arranged to act simultaneously with said clutch to hold back the driven part and prevent its moving forward relatively to the driving part.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

CHARLES E. POLLARD.

\Vitnesses:

F. O. FLADD, MARTIN J. SOHMITT. 

